How to seed an Admin user in EF Core 2.1.0?

Question

I have an ASP.NET Core 2.1.0 application using EF Core 2.1.0.

How do I go about seeding the database with Admin user and give him/her an Admin role? I cannot find an

Answer 1

Actually a User Entity can be seeded in OnModelCreating, one thing to consider: the IDs should be predefined. If type string is used for TKey identity entities, then there is no problem at all.

protected override void OnModelCreating(ModelBuilder builder)
{
    base.OnModelCreating(builder);
    // any guid
    const string ADMIN_ID = "a18be9c0-aa65-4af8-bd17-00bd9344e575";
    // any guid, but nothing is against to use the same one
    const string ROLE_ID = ADMIN_ID;
    builder.Entity().HasData(new IdentityRole
    {
        Id = ROLE_ID,
        Name = "admin",
        NormalizedName = "admin"
    });

    var hasher = new PasswordHasher();
    builder.Entity().HasData(new UserEntity
    {
        Id = ADMIN_ID,
        UserName = "admin",
        NormalizedUserName = "admin",
        Email = "some-admin-email@nonce.fake",
        NormalizedEmail = "some-admin-email@nonce.fake",
        EmailConfirmed = true,
        PasswordHash = hasher.HashPassword(null, "SOME_ADMIN_PLAIN_PASSWORD"),
        SecurityStamp = string.Empty
    });

    builder.Entity>().HasData(new IdentityUserRole
    {
        RoleId = ROLE_ID,
        UserId = ADMIN_ID
    });
}